Mechanistic Similarities between Fibromyalgia and other Chronic Pain Conditions

Lars Arendt-Nielsen, Sensory-Motor Interaction (SMI) Center, School of Medicine, Aalborg University, Aalborg, Denmark

It is generally accepted that pain diagnosis and therapy should be mechanism based and hence pain assessment tools (pain biomarkers) should be sufficiently sensitive and advanced to provide such mechanistic information. Translating clinical observations to mechanisms and vice versa is not trivial, and tools to assess quantitatively the different phenomena are mandatory. This approach has provided new insight into how reorganization of the pain system is manifested in fibromyalgia and other chronic pain conditions. Based on such studies common features across different pain patient populations have been identified. An example could be cutaneous allodynia in neuropathic pain assessed by brush, which corresponds to pain evoked by weak muscle pressure in musculoskeletal pain and to pain provoked by a weak colonic distension in visceral pain. Another example can be facilitated temporal summation and impaired descending modulation across many different chronic pain conditions including fibromyalgia.

Although assessed differently in specific tissues for various pain conditions, the underlying mechanisms share common underlying features. This mechanistic understanding is of importance for developing better diagnostics and for implementing tailored pain management programs. Some of the current available mechanistic human pain biomarkers translate back to animals, providing new possibilities for bridging findings between pre-clinical and clinical studies. Data on the clinical applicability are increasingly available.